An automobile exhaust gas purifying system including an HC absorber catalyst for absorbing HC and an NOx absorber catalyst for absorbing NOx placed upstream of an exhaust gas purifying catalyst has been disclosed, for example, in Patent Document 1. In the conventional purifying system, exhaust gas before activation of the exhaust gas purifying catalyst, is absorbed by the HC absorber catalyst and the NOx absorber catalyst. Then, after the activation of the exhaust gas purifying catalyst, exhaust gas is passed through the HC absorber catalyst or the like, and thus HC and NOx absorbed by the HC absorber catalyst or the like are separated from the absorber catalysts and purified by the exhaust gas purifying catalyst.
Including the above-mentioned document, the applicant is aware of the following document as a related art of the present invention.
[Patent Document 1] Japanese Laid-Open Patent Application No. 2005-299631